Water and steam separators for evaporators



Jan. 7, 1964 A. HUET WATER AND STEAM SEPARATORS FOR EVAPORATORS 2 Shets-Sheet 1 Filed Feb. 2, 1962 Jan. 7, 1964 Filed Feb. 2, 1962 A. HUET WATER AND SEPARATORS FOR EVAPORATORS 2 Sheets-sheaf 2' United States Patent 3,116,721 WATER AND STEAM SEPARATGRS FUR EVAPORATGRS Andre Huet, 48 Avenue du President Wilson, Paris, France Filed Feb. 2, 1962, Ser. No. 170,713 Claims priority, application France Feb. 17, 1961 3 Claims. (Cl. 122-44) In evapo-rators or thermal installations designed to convert water into steam with the aid of a hot fluid, it has already been proposed to connect the tubes of the evaporator through which flows the water to be vaporised and which are either rectilinear or in the form of helices, to vertical subheaders themselves joined to a central header which is followed by a water and steam separator, after which the steam reaches a balloon or drum containing a water surface.

The present invention has for its object to apply to an installation of this kind individual Water and steam separating devices which may be located either in the upper part of the tubes of the evaporator, or in the subheaders into which these tubes open or again, and preferably, in both at the same time.

A system of battles or bafile plates arranged inside the upper end of the tubes of the evaporator ensures a first separation and in the vertical sub header to which the tube is connected and which will preferably be inclined slightly with respect to the vertical, there is located another separating device ensuring separation, for example, by the centrifugal force assumed by the mixture of water and steam ascending inside a helical device preferably disposed within a convergent element, the steam being separated out axially while the separated water runs down towards the lower part of the sub-header, where it regains a water return tube.

Finally, separating devices may be provided at the outlet of the sub-headers into the main header.

The advantage of the fitting according to the invention of individual separating devices in the end of each of the tubes of the nest of evaporating tubes and in the sub-header or sub-headers by which they are joined resides in that it is no longer necessary to provide a separate balloon or drum for the separation of water and steam and that the steam can reach the place of use in a dry state, if required after being passed through a final separator provided at the outlet. It is therefore no longer necessary to concern oneself about a water level or about a plane of disengagement of the steam.

The description which follows with reference to the accompanying drawings given by way of example will make it better understood how the invention can be carried into effect.

FIG. 1 shows diagrammatically an evaporator comprising tubes in the form of helices which is equipped with the separating arrangement forming the object of the invention.

PiG. 2 shows on a larger scale a steam sub-header and the main steam header of the evaporator shown in FIG. 1, with the separating devices forming the object of the invention.

FIG. 3 shows diagrammatically a modified form of a detail of the outlet of a tube into the main header.

FIG. 1 shows an evaporator for producing steam with the aid of a hot fluid flowing through the conduit or jacket (1, for example in the direction of the arrow F. Inside this jacket :1, the evaporator is formed by tubes, such as b, coiled in the form of helices at a rather large pitch and arranged in such manner as to form, for example, three drums or cylinders I, II, Ill coaxial with the axis XX of the assembly. The tubes 1; are wound in coils in such manner as to be in contact at the surface of the drums or cylinders I, II, Ill. The sub-headers c, the number of which may vary, distributed over the entire periphery at the base of the cylinders I, ll, Ill feed the tubes b with water to be vaporised. As will be seen in FIG. 1, these sub-headers c have a Substantially vertical axis parallel to the vertical axis XX of the complete arrangement. The water feeding the tubes b at their bottom part b arrives in the direction of the arrow G.

The tubes b of the evaporator are connected at their upper parts to sub-headers such as d. These sub-headers are preferably slightly inclined -with respect to the vertical, as shown in FIG. 1 for the reasons which will be explained hereinafter. In each sub-header d there is provided in the upper part thereof a small Water and steam separator such as e from which the steam escapes and reaches the coaxial main header 1.

A Water and steam separator g may also be provided at the top of the header before the dry steam escapes in the direction of the arrow H. The water separated from the steam drops back to the lower part of the main header 1 and regains the water inlet at G through the tube 1:.

Each of the sub-headers d (inside which the separated water runs down as will be explained hereunder) is connected by a tube i to the lower part of the main header 1.

The mechanism of the water and steam separating arrangement forming the object of the invention will now be described in a more detailed manner with reference to FIG. 2.

Inside each of the tubes, such as b, opening at the top into a sub-header at there are provided plates j inclined after the fashion of tie slats of a Venetian blind and which have between them spaces through which the steam from the mixture of water and steam flowing through the tube 1) can be separated ofi towards the top of the drawing. Deflectors such as k are provided inside the subheader d approximately opposite the outlet of each tube 12 in such manner as to direct the water contained in the mixture of water and steam towards the lower part of the sub-header d.

In the upper part of each sub-header d the Water and steam separator takes the form, for example, of a helical incline l disposed between an axial tube in containing orifices and a convergent-divergent element 12 likewise containing orifices in its convergent portion. The mixture of water and steam rising inside the header a is subjected to a gyrating movement because of the incline l and the centrifugal force conveys the water, which is heavier, towards the outside of the helix 1, while the steam collects towards the axis of the device and passes through the orifices of the tube m to escape axially. On the other hand, the centrifuged water passes through the orifices in the convergent element n which is extended downwardly by a double wall 0 which conveys the water to the lower part of the sub-header d where it reaches, through a duct 1', the base of the main header 1 arranged axially on the axis XX of the evaporator.

The separator l, m, n which has just been described is preferably made of cast steel or other metal and inserted in the upper part of each of the sub-headers during the manufacture of the latter.

The use of small individual separators in each of the sub-headers has the advantage that by reason of the small dimensions of the device the radius of gyration of the water inside the separator is small. Under these conditions, for a given speed of flow of the mixture of water and steam, the centrifugal force being, as known, inversely proportional to the radius of gyration, the water is thrown with greater efliciency towards the outside. This effect is further accentuated by the shape of the convergent 3 portion of the duct 11 in which the radius of the helix l decreases as the mixture of water and steam advances.

The upper part of each of the sub-headers d is connected by a pipe 2 to the main header 1. Opposite the outlet of the pipe 2 into the header f there are provided deflecting surfaces q directed as indicated in FIG. 2 and which have the effect of turning any water which might still be left in the mixture towards the lower part of the header whereas the steam escapes upwardly by passing through the gaps existing between the deflecting surfaces q.

The water streaming down towards the base of the header 1 reaches at the lower part of the latter a tube 1' of smaller diameter surrounded by a double jacket s having orifices t in its top part and orifices u in its lower part. The function of this double jacket is to protect the water collected inside the tube r from the action of the heat of the hot fluid flowing externally in the direction of the arrow F. In this way, this water, protected from boiling, can flow by gravity, as shown in FIG. 1, to the tube It which carries it back into the vaporisation circuit. The small orifices u enable, if necessary, any water trapped in the double wall s to regain the water circuit, whereas in the event of more steam being formed in the double jackets the upper orifices tenable this steam to escape.

The separation of water and steam obtained with this assembly of devices is such that it is possible to dispense with any other steam separator. Nevertheless, as shown in FIG. 1, provision is made for fitting a general separator g at the outlet of the head 1 before the steam escapes in the direction of the arrow H.

FIG. 3 shows a modified form of the outlet of the tube 2 into the main header f. According to this modified constructional form, the end of the tube 2 is extended by a portion v bent in the form of a crook and in which orifices or outlets w are provided on the outer part, while outlets x are provided on the inner region of said crook v. In this way, by reason of the circular forms of the crok v, the mixture of water and steam entering the tube p in the direction of the arrow I assumes a gyratory movement and, after the steam has escaped in the direction of the arrows J through the orifices w, the water remaining in the mixture comes into contact with the inside of the wall of the outer region of the crook v, while the steam left in the mixture escapes in the direction of the arrows K through the outlets x. The radius of curvature of the crook v, the mixture of water and steam entering the tube p into the header 7 to the end of the tube p, so that the centrifugal force steadily increases as the mixture of water and steam advances.

t is obvious that modifications of detail could be made in the embodiment of this invention without thereby departing from the scope thereof. In particular, the invention could be applied to the separation of vapor from any liquid other than water.

I claim:

1. A thermal installation for transforming a liquid into Vapor by heat exchange with a hot fluid, comprising a substantially vertical conduit adapted to have a hot fluid flow downwardly therethrough, evaporating tubes extending vertically inside said conduit, means for admitting the liquid to be vaporized at the base of the evaporating tubes, upper sub-headers to each of which a plurality of said evaporating tubes are connected in groups, a main header connected to the upper sub-headers, a plurality of plane plates disposed in off-set relationship with respect to each other in succession inside the upper part of each evaporat- ,1. ing tube, the plane of each of said plates being inclined with respect to the general direction of flow of the liquid inside the evaporating tube, inwardly curved deflecting surfaces disposed in the upper sub-headers opposite the outlet of each evaporating tube into the upper sub-header to which it is connected, a liquid and vapor separating device in the upper part of each sub-header, and slightly inwardly curved plates off-set with respect to each other disposed in the main header at the outlet of each subheader into the main header.

2. A thermal installation for transforming a liquid into vapor by heat exchange with a hot fluid, comprising a substantially vertical conduit adapted to have a hot fluid flow downwardly therethrough, evaporating tubes extending vertically inside said conduit, means for admitting the liquid to be vaporized at the base of the evaporating tubes, upper sub-headers to each of which a plurality of said evaporating tubes are connected in groups, a main header connected to the upper sub-headers, a plurality of plane plates disposed in off-set relationship with respect to each other in succession inside the upper part of each evaporating tube, the plane of each of said plates being inclined with respect to the general direction of flow of the liquid inside the evaporating tube, arcuate deflecting surfaces disposed in the upper sub-headers opposite the outlet of each evaporating tube into the upper subheader to which it is connected, a liquid and vapor separating device in the upper part of each sub-header, and slightly arcuate plates off-set with respect to each other disposed in the main header at the outlet of each sub-header into the main header, and means for returning the liquid separated in the liquid and vapor separating device at the top of each sub-header.

3. A thermal installation for transforming a liquid into vapor by heat exchange with a hot fluid, comprising a substantially vertical conduit adapted to have a hot fluid flow downwardly therethrough, evaporating tubes extending vertically inside said conduit, means for admitting the liquid to be vaporized at the base of the evaporating tubes, upper sub-headers to each of which a plurality of said evaporating tubes are connected in groups, a main header connected to the upper sub-headers, each evaporator tube having its end portion bent in the form of a crook, said crook being disposed in the subheader and having orifices in its curved outer surface for the escape of vapor and orifices in its inwardly curved radially inner surface, the radius of curvature of the crook decreasing steadily as the end of the latter is approached, a vapor and liquid separating device located in the upper part of each upper sub-header, the outlet of each upper sub-header into the main header being defined by a tube rounded in the form of a crook and having orifices in its outer region for the escape of vapor and orifices in its inwardly curved inner region, whereby said tube defines liquid and vapor separating means for the fluid mixture issuing from said outlet, and means for returning to the main header the liquid separated in the liquid and vapor separating device at the top ofcach subheader.

References Cited in the file of this patent UNITED STATES PATENTS 2,240,100 Schmidt Apr. 29, 1941 3,018,764 Huet Jan. 30, 1962 FOREIGN PATENTS 1,175,619 France Nov. 17, 1953 

1. A THERMAL INSTALLATION FOR TRANSFORMING A LIQUID INTO VAPOR BY HEAT EXCHANGE WITH A HOT FLUID, COMPRISING A SUBSTANTIALLY VERTICAL CONDUIT ADAPTED TO HAVE A HOT FLUID FLOW DOWNWARDLY THERETHROUGH, EVAPORATING TUBES EXTENDING VERTICALLY INSIDE SAID CONDUIT, MEANS FOR ADMITTING THE LIQUID TO BE VAPORIZED AT THE BASE OF THE EVAPORATING TUBES, UPPER SUB-HEADERS TO EACH OF WHICH A PLURALITY OF SAID EVAPORATING TUBES ARE CONNECTED IN GROUPS, A MAIN HEADER CONNECTED TO THE UPPER SUB-HEADERS, A PLURALITY OF PLANE PLATES DISPOSED IN OFF-SET RELATIONSHIP WITH RESPECT TO EACH OTHER IN SUCCESSION INSIDE THE UPPER PART OF EACH EVAPORATING TUBE, THE PLANE OF EACH OF SAID PLATES BEING INCLINED WITH RESPECT TO THE GENERAL DIRECTION OF FLOW OF THE LIQUID INSIDE THE EVAPORATING TUBE, INWARDLY CURVED DEFLECTING SURFACES DISPOSED IN THE UPPER SUB-HEADERS OPPOSITE THE OUTLET OF EACH EVAPORATING TUBE INTO THE UPPER SUB-HEADER TO WHICH IT IS CONNECTED, A LIQUID AND VAPOR SEPARATING DEVICE IN THE UPPER PART OF EACH SUB-HEADER, AND SLIGHTLY INWARDLY CURVED PLATES OFF-SET WITH RESPECT TO EACH OTHER DISPOSED IN THE MAIN HEADER AT THE OUTLET OF EACH SUBHEADER INTO THE MAIN HEADER. 